1. Field of the Invention
The present invention relates to a multi-layer image display system and method thereof, in particular, which can display a three-dimensional image according to depth so that the three-dimensional image can be transferred to a user without incurring eyestrain.
2. Description of the Related Art
In general, the most prominent problem is eyestrain in obtaining the three-dimensional image. It is due to the fact that an electronically realizable three-dimensional image display mechanism of the related art does not enable the three-dimensional image to correspond to all of the basic optical functions of eyes. Furthermore, the three-dimensional image display mechanism of the related art restricts a viewing zone or a zone viewable of the three-dimensional image thereby adding inconvenience in viewing posture.
A majority of three-dimensional image display systems of the related art take pictures of a plane image of an object, which is to be displayed into the three-dimensional image, by using at least two cameras horizontally arranged at a predetermined interval considering compatibility with conventional two-dimensional plane image display systems. Then, the system projects the plane image on a visual zone defining screen according to time or space splicing or directly displays the plane image on a display device with a visual zone defining optical plate to obtain the plane image of the object three-dimensionally so that the three-dimensional image can be recognized. The three-dimensional image display system using this mechanism allows eyes to sense depth through the plane image by using binocular parallax or binocular parallax together with moving parallax.
Therefore, even if the plane image is recognized as the three-dimensional image due to parallax, the image itself is a plane image focused to the surface of a screen or a display device, and thus fails to correspond to other functions of the eyes such as convergence and accommodation. Namely, since the image can be vague and unseen due to the operation of the functions such as convergence and accommodation when a line of sight is moved from the screen or the display device, the eyes should repeatedly focus on the screen or the display device surface. Therefore, repeated movement of the eyes is required to recognize the three-dimensional image through the three-dimensional image display system of the related art thereby incurring eyestrain or fatigue to the eye.
Methods for producing a depth-sensible display image have been proposed to overcome the foregoing problem. The methods include a method of electrically displaying a hologram and a volumetric image method for displaying layers divided according to depth.
The hologram method, however, requires that the display panel and a photographing device have similar size and a predetermined area of high definition is ensured since a angular field decreases according to expansion of a hologram. Such requirements cannot be electronically realized at the present.
Also, the volumetric image method includes a method of projecting the images according to layers synchronized with a rotating helical screen, a variable-focal mirror method of reciprocating a spherical mirror synchronized with the images according to layers, a Laser Scanning Volumetric Imagine System, and the like. However, these methods are based upon the image projection and do not sufficiently use the previous flat panel display device such as an LCD or the CRT.
Besides, while a number of LCD panels can be arranged by using the conventional flat panel device, the LCD panels are required as many as the images according to layers. Therefore, light efficiency is very low and other display devices rather than LCD cannot be adopted.
The present invention is proposed to solve the foregoing problems of the related art, and it is therefore an object of the invention to provide a multi-layer image display system and a method thereof which can obtain a three-dimensional image corresponding to four basic optical functions including binocular parallax, moving parallax, convergence and accommodation to prevent eyestrain.
According to an embodiment of the invention to obtain the object, it is provided a multi-layer image display system comprising: a plurality of plates rotating in sequence about a rotary axis; a plurality of image display units mounted to said plurality of plates toward a user side for displaying an image; and a plurality of light source units placed in positions corresponding to said plurality of image display units as opposed to the user side about said plurality of plates for illuminating said image display unit, and a method thereof comprising the following steps of: (a) generating the multi-layer image sampled from a stereoscopic image according to depth to display the stereoscopic image; (b) displaying layer images composing the multi-layer image generated in said step (a) to image display units mounted to a plurality of rotary plates according to depth without overlapping; and (c) stereoscopically transferring the images of the image display units to a user.
According to another embodiment of the invention to obtain the object, it is provided a multi-layer image display system comprising: a plurality of plates rotating in sequence about a rotary axis; an image projection screen unit mounted to said plurality of plates for allowing an image to be projected; and a plurality of projectors for projecting the image to said image projection screen unit, and a method thereof comprising the following steps of: (a) generating the multi-layer image sampled from a stereoscopic image according to depth for displaying the stereoscopic image; (b) projecting from a plurality of projectors layer images according to depth so that the layer images composing the multi-layer image generated in said step (a) are generated with depth difference; and (c) stereoscopically transferring the layer images to a user as a plurality of image projection screen units corresponding to a plurality of projectors rotate without overlapping with one another and the layer images projected from the projectors are formed on the image projection screen units.
According to further another embodiment of the invention to obtain the object, it is provided a multi-layer display system comprising: a plurality of image display units for displaying a plurality of layer images composing a multi-layer image; a reflecting means for reflecting the layer images, whereby the layer images displayed from said image display unit are obtained in a multi-layered manner so that a user can stereoscopically see the layer image; and a rotary means for rotating said reflecting means to sequentially reflect the plurality of layer images displayed on said plurality of image display units, and a method thereof comprising the following steps of: (a) generating the multi-layer image sampled according to depth from a stereoscopic image to express the stereoscopic image; (b) displaying layer images composing the multi-layer image on image display units; (c) reflecting the layer images displayed in said step (b) through a plurality of reflecting means rotating without overlapping; and (d) stereoscopically transferring the layer images to a user as the layer images are reflected through the plurality of reflecting means in said step (c) and obtained in a multi-layered manner.